Section 178.338-6 - Manholes(a) Each tank in oxygen service must be provided with a manhole as prescribed in Section VIII of the ASME Code (IBR, see §171.7 of this subchapter).(b) Each tank having a manhole must be provided with a means of entrance and exit through the jacket, or the jacket must be marked to indicate the manway location on the tank.(c) A manhole with a bolted closure may not be located on the front head of the tank.Amdt. 178-77, 48 FR 27704, 6/16/1983, as amended at 49 FR 24316, 6/12/1984; 68 FR 75754, 12/31/2003